Fire-alarm system



V. DURBIN' FIRE ALARM SYSTEM Original Filed June 23, 1922 film 3M 47[l i 1. J J 1 w 3 i -1. a Mfi u A... 1 m m E. film 1 0 s a 11 L v 3 @5 w 2 Dec. 30

Dec. 30, 1930. v B'm 1,786,524

' FIRE ALARM SYYSTEM Original Filed June 23, 1922 7 Sheets-Sheet 2 mtzzg zlflw e z'r-gws skw LIMRekg FWZ I I l I l i I LJLJ 7} 47 I 6 34/6: B65 i Dec 30, 193(). v DURBIN 1,786,524

FIRE ALARM SYSTEM Original' Filed June 23, 1922 7 Sheets-Sheet s w izfaeszs" mm? 17 @iizfim Dec. 30, 1930. v. DU RBIN 1,786,524

FIRE ALARM SYSTEM.

Original Filed June 23, 1922 7 Sheets-Sheet 4 Dec. 30, 1930. v. DURBIN FIRE ALARM SYSTEM Original Filed June 23, 1922 '7 Sheets-Sheet 7&23524551 Dec. IN), 1930. v, DURB|N 1,786,524

. FIRE ALARM SYSTEM Original Filed June 23, 1922 '7 Sheets-Sheet 6 V. DURBIN Dec. 3Q, 1930.

FIRE ALARM SYSTEM Original Filed June 23, 1922 '7 Sheets-Sheet 7 Patented Dec. 30, 1930 UNITED STATES PATENT OFFICE VERNON DUBIBIN, OF NEWTON, MASSACHUSETTS, ASSIGNOR TO THE HOLTZEB-CABOT ELECTRIC COMPANY, 01 BOXBURY, MASSACHUSETTS, A CORPORATION 'OI' MASSA- CHUSETTS Irma-arm srsrmr Application filed June 28, 1922, Serial The present invention relates to an improvement in fire alarm systems.

The object of the invention is to produce a fire alarm system of simple construction and .8 less expensive than systems now in use.

Another object of the invention is to produce a fire alarm system in which the alarm boxes are so constructed and arranged as to be noninterfering and successive in operation. Another object of the invention is to produce a system comprising a plurality of box circuits, or a multiple box-circuit system, which is non-interfering and successive in operation. Other objects of the invention will be set forth in connection with the description of the invention.

To these ends the present invention consists in the fire alarm system and constructions hereinafter described and particularly 9 defined in the claims.

In the accompanying drawings illustrating the preferred form of the invention, Fig. 1 is a diagrammatic plan illustrating the complete system; Fig. 2 is a diagrammatic plan wherein the details of a portion of the system are illustrated; Fig. 3 is a diagrammatic plan of the fire alarm system, giving emphasis to features of construction relating to the securing of non-interfering and successive operation of the box circuits of the system; Fig. 4 is a front elevation of the box mechanism; Fig. 5 is a rear elevation of the same; Fig. 6 is a top plan of the same Fig. 7 is a section taken on the line 7-7, Fig. 6; Fig. 8 is an illustrative diagramjof portions of the box and connections; Fig. 9-is a more or less diagrammatic sketch of the line relay and associated parts, and Fig. 10 is a diagrammatic plan of a single box-circuit fire alarm system. 7 I

The preferred embodiment of the invention is described as follows:

Multiple bow-circuit system.-v-The general systemis illustrated in Fig. 1.' Box circuits B B are shown in double lines. All of the apparatus shown is at the central station with the exce tion of the box-circuits shown at the top of t e figure and the station signals shown at the bottom of the figure. The boxes 1 are all alike, and when pulled operate to 110. 570,393. Renewed an -1a, me.

send insignals to the central station. Each A box circuit is provided at the central station with a line relay LR and associated elements, and a non-interfering relay NIR, which is connected with the non-interfering lines NIL,

and operates to prevent the different box cir-.

the receiving of signals from any box in any circuit. Each box circuit is provided with a pole changer PC, operated by the line relay on the pulling of a box to reverse the polarity of a box circuit. Broadly considered, this may be stated to be a device for abnormalizing the box circuit current, and viewed in such aspect it is immaterial whether it is abnormalized by reversal or in a variety of other ways. When a box in a box circuit is pulled, it breaks the circuit, and the break in the box circuit operates, through means to be described, to de-energize the pole changer PC, which thereupon operates to reverse the polarity of the box circuit. The reversal of polarity of the box circuit operates to pre- 'vent any one of the boxes in such box circuit from sending in a signal in a manner which will be described in connection with a description of the box. Thus, whenever a box is pulled, and has gained control of the box circuit, it will begin to send and continue sending the signal of the box to the central station until it has completed the sending in of-the signal. After the completion of the signal the pole changeris re-energized, and the polarity of the box circuit is restored to normal, or normalized, whereupon any other box in that line which has been pulled will beginto operate, and the first one of such boxes which gets control of the line will cause the breaking of the box circuit, and the reversal of polarity thereof, and thus prevent the sending in of signalsfrom any other box until it has completed the'sending in of its signal. The non-interference of the boxes in one box circuit is controlled by the reversal of polarity of the line, for when the polarity is reversed no box can send in any signal except the box which. first broke the circuit. Each box circuit operates a box circuit signal BC S, so that when a signal in being sent in, the central station apparatus of the box circuit gives a signal audibly and at the same time records it.

Each; box circuit is provided with a trouble indicator TI, which sounds a bell and lights an indicator lam when the box circuit remains open for a lbn h of time greater than that suflicient to sen in a signal from a box; The trouble indicator circuits are shown in broken lines. Thus, in case a box circuit line should be accidentally broken, thiswould result in abnormalizing the circuit, and then, after the lapse of a certain length of time, the box circuit at the central station, through the line relay, would be restored to closed condition, and the trouble indicator TI would. ring a bell and light a lamp, and thereby call attention to the out-of-o'rder condition of the box circuit. At the same time this device operatesin addition to prevent such open box circuit from interfering with the operation of any other box circuit, so that the accidental breaking of one box circuit will not put thewhole system out of commission, but will result only in the puttingout of commission of the particular box circuit which is broken; The non-interferin relay NIR is connected with the non-inter e'ring relays of the other box circuits, thearrangement being such that when one box circuit is opened, the non-interfering relay operates a ma et in all the other non-interfering relays o the system to open all the box circuits except that" box circuitin which the signal first-originated. 1 These non-interfering lines. conveniently afiord a connection to a station signal relay SSR which makes and breaks the station signal circuit. Thus, when a box circuit begins sending in a signal, the signal is given by the box circuit signal, and in addition the station signal relay impresses these signals upon the station signal circuit SSC, which runs to all the stations inv the city, and in each one of those stations gives the signal and recordsit at those stations. 7

Thus, it will be seen that each box circuit provides for the separate, successive and non- Interfering sendingin of signals from each box, and the central station provides for the separate, successive and non-interferin reception of signals from each'box circuit as well as the separate, successive and non-interfering sending out of station signals on the station signal ci cuit.

Bow drwz't.Referring to Fig. 2 in which the box circuit is indicated in double lines and the line relay LR is shown with its various zconnectior 3 wherein the trouble circuits are shown in broken lines, and the non-interfering circuits are shown in heavy lines, we have the following arrangement: The box circuit B is provided with a pole changer PC, which consists of a magnet, and apparatus for reversal of v the polarity of the box circuit. Such apparatus is well known and needs no specific description here. Suflice it to say t at the switch members 10, upon the de-energization of the pole changer circuit, move mm the position shown in Fig. 2 into contact with the lower contacts of the pole changer, so as thereby to change the polarity of the box circuit B The left hand side of the box circuit is connected at the binding post 11 with the line relay panel. From this binding post'the circuit leadsto the line relay 12, and thence to the binding post'13,"by the wire 14. A. tap 15 from the near side of the box-circuit battery leads (through the binding post: 77 and connection 78) to the armature 16, and-upon the opening of the box circuit B, the relay 12 is de-energized and the armature 16 falls, thereby closing the circuit through the wire 17 to the time element relay 18, thereby energizing the latter, and causing it to attract the armature 19. This with draws the armature 19 out under the contact pin 20, which is rotated motor 21, as seen inFig. 9.

To di ess for the moment for the purpose of describing this relay and its mode of operation, it is pointed out that the armature 19 carries the pivoted bar 22, which at its upper end is. provided with a shoulder 23 u on which the'contact pin 20 rests when the time 7 element relay ,18 is de-energized. The upper end of the bar 22 also carries a feed-pin24, supported on the bar 22 in a block of insulating material 25, the end of which pin engages the screw thread 26 on therotatin shaft 27,

driven by the spring motor 21. en the shoulder 23 is withdrawn from under the contact pin 20, a circuit through the spring motor, the contact pin and bar 22 is opened. When the armature 19 is attracted by the relay 18 and the bar 22 is withdrawn from un der the contact pin 20, the spring 28 swings the bar 22 on the pivot 29, and thus the pin 24 is moved toward the spring motor box, andv then upon the next de-energization of the time relay magnet 18, as when the box circuit begins sending in its signals, the armature 19 beingreleased, the pin 24 is swung intoengagement with a screw on the shaft 27. Thisscrew is of such length that the screw willnot feed the pin 24 far enough'to move the shoulder 23 under the contact pin 20 during the sending in of a signal from a box, but will require a longer time, than the sending in of the longest signal to bring such shoulder under the contact pin. The armaturefis pivoted at the bottom as shown and a spring 30 normally holds the armature away from the magnet and inthe position shown in Fig. 9. It is thus seen that the dropping of the armature of the line relay 12 breaks a circuit conby the spring trolled by the time element relay. This circuit thus broken by withdrawal of the lever 22 from under the contact pin 20 is the pole changer circuit. The pole changer circuit extends from a tap 31 on the wire 15 through the wire 32 to the armature 19 and thus through the contact pin 20 to the frame of the spring motor 21, from which the wire 33 leads to the pole changer PC. The return wire 34 from the pole'changer leads to the binding post 35, which is connected to the opposite or far end of the box circuit battery 36 from that to which the left hand side of the box circuit is conected.

' Thus, the opening of the box circuit deenergizes the line relay, lets fall its armature, closes the time-element relay circuit, which causes itsarmature to open the polechangerv circuit, whereupon the box circuit is reversed. The box circuit remains reversed or abnormalized until the sending in of its signal is completed; specifically, it remains =reversed until the pole-changer circuit is the lever back to its original tripped posi-' again closed. The spring motor' 21 and the time-element rela 18 act to prevent the closing ofthe pole-c anger circuit by preventing the contact pin 20 from engaging with the shoulder '23 of the bar 22, and thereby closing the pole-chan er circuit for a certain length of time. Durlng the s'endingin of a signal the opening of the box circuit due to such signal sending closes the circuit through the time-element relay magnet 18 and pulls the pin 24 out-of engagement with the screw 26, and thereby permits the spring 28 to pull tion. The screw 26 on the spring motor shaft 27 is made of such a length as to prevent the bringin of the shoulder 23 under the contact pin 0 for a length of time greater than the longest interval during the sending in,

of a signal from the box. When the box I ceases to send in signals the .energization of the time-element relay magnet 18 ceases, and

the feed pin 24 remains in contact with thescrew 26,'and thereby the lever. 22 is swung against the tension .of the spring 28 until finally the contact pin 20 engages the shoulder 23 of the lever 22, thereby again closing the Pole'changer clrcmt and restormg the 1 nected to the far end of the box circuit batpolarity of the box circuit to normal.

In connection with each box circuit there is employed a trouble apparatus which operates on the accidentalopening of the box circuit,'after the lapse of a certain period I box circuits. At the same time, this trouble apgaratusdights a lamp'and rings a gong, an the light remains lit and the gong continues to ring until the trouble is eliminated or the attendant opens the trouble line. The

trouble circuits, it will be recalled, are shown in-broken lines.

While this apparatus-1s shown as conveniently embodied in 'a construction employing veniently inserted at this place because of the identity of the spring motor 21, which serves the two functions, both of reversing the polarity of the box circuit, and of ultimately closing the station portion of the box signal circuit.

To the binding posts 50 and 51 there are connected wires 52 and 53, which. lead to the non-interfering relay or relay panel NIR, a description of which will be found at a later place. Sui'fice to say for the purpose of the present description that the non-interfering relay ope and closes the circuit with which the bin ing posts 50, 51 are connected, and thus ener izes and de-ener izes the trouble relay 54. 3y reference to ig.-9 again, it will be seen that when the trouble relay 54 is energized, it attracts its armature 55 to which the arm 56 is pivotally attachedin a manner similar to that in which the bar 22v ture away' from the magnet and in the position shown in Fig. 9. The upper end of the pivoted bar 56 carries a knife 59, which, when the trouble relay 54 is energized, engages the screw thread 26, and thereby feeds the arm along. to the right, as shown in Fig. 9, and as it a proaches the end of its movement to the rig t, itengages the switch 61 and moves it to the right into engagement with the contact 62, the arm 56 being provided with an insulated portion 63 adapted to engage the switch 61 for this purpose. The switch point and a spring 58 normally holds the arma- 62. is connectedby the wire 63' tothe box circuit B at a point 64 above the line relay 12 The switch lever 61 is connected by the wires 65 and 34 with the binding post 35 contery 36, so that when the trouble relay 54 re mains closed for a suflicient length oftime I to feed the arm '56 over sufliciently far to cause it to engage and move the switch lever 61, this'switch is closed and the line relay is re-energized exactly as if the box circuit "were closed. Thus the box circuit B although it remains open due to some accident,

can no longer interfere with the operation of other box circuits and prevent the receiving 9f signalsfrom them. At the same time that this-trouble circuit is closed, as above described, the switch lever 61 makes contact with the contact 79 which conveys current a lamp 72, the former of which rings and;

the latter of which remains illuminated until the box circuit connected therewith is reaired or the attendant interferes. The wire 3 leads from the binding post 68 to the trouble indicator TI, and the wire 74 leads tothe binding post 75, which in turn is connected by means of the wire 76 with the binding post 77, connected by means of the wire 7 8 to the near side of the box circuit battery 36.

Each individual. box circuit is provid with its ownbox circuit signal device BCS. For this urpose the connections from the non-intert rence relay through the wires 52 and 53 are availed of. This relay, as will hereinafterappear in detail, operates upon.

the making and breaking of the box circuit to break and make the circuit through the trouble relay 54. So a tap wire 40 from the wire leading from the binding post to the trouble relay 54 leads to the binding post 41, front which the wire 42 leads to the box circuit signal BOS,1indicated on Fig. 2 as 43, but which comprims, aswill be seen by refer- 'ence to Fig. 1, a bell 44 and permanent record 90 apparatus 45. From the box circuit signal .nal being made. 1

the Wire 46 leads to the binding post '47, which is connected by the wire 48 with the binding post51. Thus, uponevery energization of the non-interference relay magnehthe box circuit signal BCS gives and records the sig- In the fore oing description tr theconnections more irectly concerned with the box circuit system, the non-interfering relay NIR has been generally referred to, and it now is convenient to describe its construction and mode of operation in detail. 7

Referring to Fig. 3, the non-interfering relay is shown so that its construction and mode of operation may be understood. The box circuit line B coming from the binding post 13 is connected to the binding post 81 of the non-interfering relay NIB. From there.

it runs to the relay proper-.82 from which itreturns'to the binding 0st; 83,.and thence passes to the near side 0 the box circuit battery 36. The relay 82 is provided with an. armature 84'normally 'held'in lifted position "by the closed box circuit B}. 'When the box circuit is opened, this-relay 82 is deener ized and the armature 84 falls. When it fa is it performs a number of functions, (-1) to close the circuit at contacts 100 and 105 through the trouble relay 54 (Fig. 2) through the medium ofthe connections 52 and 53,, thereby starting up the trouble circuit closer: 61 which will operate toclose the box circuit in case it does not otherwise close in due course after the sending in of the signal, (2) to closet-he circuit through the non-interfering relay wease panels of all the other box circuitsB, etc.,

ment, and third the box-circuit-interference-.

prevention arrangement.

The trbuble arrangement comprises a wire leading from the battery line 92 to the bindincr post 96, thence to the binding post 97, an through the lines 52 and 53 to and from the trouble relay 54 (Fig. 2), and back to the bindingpost 98, which in turn is connected by means of the wire 99 with the contact 100 adapted to beengaged by-the armature 8401f the non-interfering relay 82. The armature is connected by means of :1 wire 101 leading to the binding post 102 which is connected. by the wire 103 to the battery line 93. Thus when the box circuit B is opened and the relay 82 is die-energized, the falling of the armature 84 makes a circuit through the trouble line and trouble relay, and thus prepares the apparatus to short-circuit the box line, incas'e the box circuit should remain open for too long a time,'a nd in addition it afi'ords a means for giving-the box-circuit signals. It will be seen from Fig.2 that if the box circuit stays open sufliciently long to allow the trouble relay to actuate the switch-61, a short circuit path for the box circuit is provided, as above described,-so that if the box circuit remains open-due to any fault therein, such conditionis' ineliective toactuate an of the apparatus or cause interference wit the other circuits. 1.

Coming now' to the non interferingand repeating arrangement. Simultaneously with the fall of the armature 84 of the relay 82 by the opening of the box circuit B the armature 84' akes contact with the contact 105, and th'e'rdby leads current to. the box-cirhuit opener line 94 through the wire 106 leading to the binding post. 107, connected by means of the wire, 108 to the box circuit,

" bpener' line 94. 94 at each of the other box circuits theiwires 108lead current .to the magnets 109, from which the current leads through the wire 110-, binding post 96 and wire 95 to thebattery- 11119192, thus energizingthe magnets 109 and attracting the armatures 111, which pull with them the. pivotedswitch levers 112., and open the 'far or 'right hand sides of the box circuit lines at 85. It willbe observed that theiarmaturo 111 and lever 112 are connected by means in position to the right, as shown in of the insulating link 113-and normall held ig. 3 by means of-the spring 114. The magnet 105 and its armature 111 constitute a circuit opening relay which is operatedon the enerthat the energization of the magnet 109, pulling as it does the armature 111 under the end of the armature 84, prevents that armature from dropping on the opening of such'inactive box circuit, and so long as one box circuit is sending in a signal all of the other box circuits are thereby prevented from operating at all. The magnets 109, it will be noticed, are arranged in multiple, and the current is supplied at the contact 105 by the active box circuit.

The box circuit interference prevention arrangement-The opening of any box circuit will de-energize the relay magnet 82 of that box circuit, and thereby close the circuits through all of the other non-interference magnets 109, thereby opening all other box circuits. The eflfect ofthis upon the other box circuits will be to de-energize all their line relays 12, (Fig. ,2) reverse the polarities of such circuits, or abnormalize them, and thereby hold them inoperative to send in any signals pending the receipt of the signals from the active box circuit. When the sending in of a signal from a given box circuit is completed, the polarity of such circuit will be reversed by the energization of the pole changer of such circuit, whereupon, the circuit'being' remade, the non-1n: terfering relay magnet 82 will be again-energized, and its armature raised, thereby opening the circuit leading to the several non-interfering magnets 109 in the non-lnterference relay panels, and permitting the springs 114 to'close the far sides of all-the box circuits, whereupon any box in any other circuit which has been pulled, or the pulling of a box in any box circuit may re-instltute the sending in of a signal.

Signal bomes..-The general system and the box systems have been described, together with their mode of operation, and it now remains to describe the construction and mode of operation of the several boxes which have features of construction for preventing interference between boxes on the same box circuit, and securing successlv ty of operation of boxes which have been pulledsimul t'aneously. In this connection, the word simultanenously is to be understood as meaning pulled within the time limit of operation of a box thus, if a box is pulled, and starts sendlng 1n a signal, it gains and holds control of the line until it has completed the sending in of its signal. If another box is pulled duringthis time, the second box may be said, 1n a sense, to have been pulled simultaneously with the pulling of the first box, but it will be moperative, by reason of features of construction presently to 'be' described, to send in a signal until the first box shall have completed the sending in of its signal.

The box is shown diagrammatically in Fig. 8, the line wire 200 leading to the box, and the line wire 201 leading away from the box, and the box being short-circuited by the cover 202, which interposes a connecting plug 203 between the contacts 204 on the line 200, and the contact 205 on the -line '201, so that in normal condition, with the box closed, the box is short-circuited out of the box circuit line. The line at this time has a normal direction current, or a normal current, and whenever the cover of one of the boxes is opened, this current passes through the noninterference magnet206 and causes it to attract its armature 207, thereby holding it in a position below the end of the code lever 208. At this time the code lever is in its left hand position, as shown in Fig. 8, and the signal contacts 209 are-closed and the current con tinues from such .contacts through the wire 210 to the polarized magnet 211, which, owing tothe normal condition of the current flowing through the box, is of such polarity as to hold the armature 207 of the non-interfering magnet 206 within the effective field of such magnet. This is secured by means of an arm 212 attached to the armature 213 of the polarized magnet, which arm 212 presses on a projection, or finger on the armature 207 of the non-interference magnet, and depresses it into a position within the efiective field of the non-interference magnet. When the armature 207 is held-depressed, whether by energization of its magnet or by the arm 212, the armature 207 permits the code wheel to turn by virtue of aconstruction presently to be described. Y

Now, assume that the box is -pul1ed, by-

cuit. This breaking of the box circuit results first in the de-energizationof the polarized magnet, and thereupon the spring 214 raises the arm 212 and withdraws it from contact with the projection on the armature 207. At

the same time the non-interference magnet 206-is'de-ene1 gized by the breaking of the circuit, but its armature cannot rise because the right hand position of the code lever prevents, so the code wheel continues to turn.

These are the operations which take place at the box.

Now the central station is caused, by the breaking of a circuit to reverse the connections of the battery to the box circuit and to thereby prepare the box circuit for the re ceptionof reversed current or abnormalization. This immediately follows the opera-.

tions above described,'as soon as the code wheel turns far enough to push the code lever to the left and thereby close the circuit again. at the contacts 209. This closure of the box circuit at these contacts initiates the sending in of the signal from the box, and does nothing else because all of the other boxes are held inoperative by reason of the previous opening of the circuit, their armatures 207 having risen under the influence of their springs, thus bringing their ends in front of their code levers 208, in whichposition'they are beyond the effective field of magnetism of.

their non-interference magnets 206, as a consequence of which they remain in raised position, and although the circuit is opened and closed-in the process of sending in the signal from. the operating box,.such arinatures remain stationary and hold their code wheels from motion in a manner above referred to and presently to be more specifically described. This reference to dther boxes, of

operating mechanism. The code wheel 221i is. supported in the usual manner on the plate 220. The shaft 222 upon which the code wheel is mounted carries a pinion 223, which is driven by the gear 224; to the latter is secured the pinion 225which is actuated by the segmental gear 226; this gear in turn is driven by the spring 227, which spring is wound up by the pull-lever 228 in the usual manner. The code wheel shaft 222 carries the gear 229 which meshes with the pinion 230, which in turn is attached to the escapement wheel 231. This escapement wheel drives the escapement 232, which acts as a device to regulate the speed of motion of the code wheel" 221. When the pull-lever 228 is pulled down and thereafter released, the code wheel starts in motion, and the latter rotates at a rate of speed determined by the cscapement 232. v

The non interfering magnet 20,0 is mounted extends outward from the on circuit by the openmeauae with its tooth resting upon the stopping land 242, as shown in Fig. 45, which holds the code lever 208 in left hand position, so that its insulating pusher block 2&3 holds the contacts 209 closed. With the code lever in the posi-, tion shown in Fig. 4., that is, in its stop: ping position, it will be observed that the armature 207 of the non-interfering magnet may, if permitted, rise so that its end will come in front of the lower end of the code lever, and thereby prevent the code lever from moving to the right. When the code lever is moved to .the right, its lower end. swings over the end of the armature 207 and prevents the latter from rising. -The arma ture 207 is provided with a tin or 244, which of the armature, as shown in Fig.6, and thence through a hole 2451s the plate 220 and beyond and into the path of a pin 246, projecting from: the side of the escapement 232. .Thus' when the ma et 206is energized and the anima ture 20 is held downward, the finger 2 14 is held below the pin 246, so, that the clock. work mayoperate, and the code wheel may rotate. So, therefore, when the code'levcr is sending in. a signaland moving from left to right to open and close the contacts 209. the armature lever is held down by the code lever when ,the contacts 209 are separated, that is to say, when the box circuit is open. Then when the code lever moves to the left and closes the contacts 209, this energizes the non-interfering magnet 206, and holds the armature 207 down so' that, it cannot rise while the code lever is in the left hand position. With this arrangement the sending in of asignal by the box is accomplished, the code lever holding the armature 207 down, while the circuit is open, and the magnet holding the armature down when the circuit is closed, and the rotation of the code wheel being permitted by the holding down of the armature by either. the one or the other means.

The polarized magnet 211 is provided with 7 an armature 213, which is shown in normal position in Fig. 8. This armature is provided, as has been stated, with the arm 212 which extends from the armature to a position above the finger 244. Now when the current pass,- ing through the polarized magnet is direct.

or normal current, the arm 212 is held depressed, as. shown in Fig. 8, and this holds the armature 207 downin the field of the noninterfering magnet 206. Upon the pulling of the box the box circuit is brokenby reason of the fact that the code lever moves to the right and drops oh the stopping land 2 12 of box circuit the polarized magnet 211 is de-' energized, and the spring 214 lifts the arm 212 so that it no longer operates to prevent the armature 207 of the non-interference magnet from movement, but as the armature is held down by the code lever at this time, the code wheel is permitted to continue to rotate. The opening of the box circuit operates at the central station to cause the pole changer to operate, thereby reversing the box circuit connections, then as soon as the .code wheel moves far enough for a tooth to push the code lever to the left and thereby close the contacts 209, reversed. or abnormal current flows through the box circuit and prevents the non-interference ma-gnet'of any other box from operating todepress its arma ture as abovedescribed. Upon the completion of the sending in of the signal, which is commonly repeated four times by four revolutions of the code wheel, the'code lever is moved to the left by the stopping land 242 of the code wheel, and the line relay 12 is energized, thereby lifting its armature and breaking the circuit through the time element relay 18, which'permits the pin 24 to engage the screw 26 of the spring motor 21, so that the lever 22 is moved .to the right, as shown in Fig. 9, and the shoulder 23 is ultimately presented to the contact pin 20. which it arrests, at the same time closing the pole changer circuit and reversingthe polarity of the box circuit, and thereby restoring it to normal. This restoration of the box circuit to normal causes the polarized magnet armature to re-assume the position illustrated in Fig. 8, thereby holding the non-interference magnet armature 207 depressed.

The non-interference of two boxes on one box circuit is secured by the cooperation of the non-interference magnet with the code .wheel, because once a given box shall have ained control of the .box circuit, the send- 'mg in of'a signal from such box cannot be interrupted by the other boxes. .This is due to the fact that the polarity of the box circuit is reversed, or abnormalized, and any other box the door of which is open, and the lever of which is pulled, will, due to the reversal of polarity of its polarized magnet, swing its arm 212 upward, thereby permitting, on the first'br eakof the circuit at the operating box, the armature 207 of such second' box to-rise into position opposite the lower end of the code lever of that box, thereby preventing it from'dropping into the depression at the end of the land 242, and at the same time the finger 244 of the noni-nterference magnet leverwill be in front of the pin 206 of the escapement, and the code wheel of such second box will thereby be held stationary. until the first box completed' the sending in of'itss ignal, and causes The withdrawal of the finger 244 of such second box from in frontof the escapement will permit the code lever to drop into the depression beyond the stopping land 242, and

that will secure the opening of the contacts 209 of such second box, and thereby again reverse the polarity of the box circuit, and thii, second box will begin sending in its signa Any number of boxes in a box circuit may have their doors opened, and their levers may be pulled at identically the same time, but in one of such boxes the tooth on the code lever will drop into the depression at the end of the stopping land before the corresponding code lever in the other boxes drops into such depression, and thereupon such first operating box will gain control of the-line, andthe other boxes will be held the completion of the sending in of the signal from the first box. Thereupon the polarity of the box circuit will be restored to its normal condition, and all of the boxes will start to rotate their code wheels, until one of them gains control of the line and stops the others until it has sent in its-signal.

Froma consideration of the foregoing description of the signal as a whole, and the box circuit as an integral part of it, it will be seen that the boxes in each box circuit are non-interfering and successive in operation, and each operates under the power of the spring motor, which is wound up by the pulling of the box'lever. It willbe further seen that the several box circuits are non-interfering and successive, in the same manner as the boxes of the signal box circuit. It is not, however, to be understood that one box in one box circuit having gained control of the system, such box circuit will retain control of the system until all of the boxes in such ders. the entire system non-interfering and successive as to all of its boxes, and all of its signals.

- It Wlll be seen that the non-interferenceits ence and successlvity of a box circuit, renm be open) the code lever 208 is necessarily in such position as to permit the armature 207' to rise to a position out of the efi'ective field of the magnet. The armatureis permitted thus to rise because since the line is open, the polarized magnet is deenergized and the arm 212 has been raised by the spring 214. Such a box can not regain control of the system until the armature 207 is moved within the effective field of the ma 50 action being brought about by t e normalization of the box circuit current which restores .the retaining arm 212 to the position shown in Fig. 8. Since a box is inoperative to transmit a signal if it looks into an open line .5 when it is itself closed,-it is apparent that there can. be no interference between boxes on the same circuit or boxes on different cir-- cuits. The non-interference between boxes on different circuits is efiected by the operaso tion of the non-interference relays which open and close with eachopening and closing of a box circuit in accordance with the operation of the code lever of a box which is transmitting a signal. Thus, when an active 86 box circuit is transmitting a signal through operation of (meet its boxes, all. other box circuits are opened and closed in synchronism with the: movements of the code lever of the operating box. This opening and closing of allbox, circuits in synchronisrn with the operationof a single active box, affords a means for preventing transmission of a jumbled signal in the event that two boxes should happen to gain controlof the line at 5 'exactlythesame instant of time.

two boxes are on the same box circuit, both will be permitted to operate so long as they act inexact unison'but because of the necessarily diiferent code wheels on the two boxes,

a time will eventually come when one of the boxes will be closed and the other open. The

' box which is closed will then lose control of the line because it is looking into an open M line and the other will continue transmission a r. of the signal. This same action results if two boxes in different circuits gain control at the same instant. So long as they operate in unison, may open and close their box circuits 0 together, but eventually one-of the boxeswill open its circuit whilethe other box and its circuit are closed. The action of-the former box in opening its own box circuit operates ,through the non-interference relaysto open 06 all other box jcircuits includingthe box circt 206, this If such the a paratus to secure the mo cuit of the second box. This second box will therefore look into an open line and lose con trol'ot the system, permitting the first box to complete thetransmission of a clear signal.

A feature of construction of the line relay 12 andthe non-interference relay 82 should be referred to by virtue of which their capacity to support their armatures is not destroyed by the sli ht interval of time. which is required for t e operation of the pole changer. That is to say, these magnets are of the kind known as slow-acting, having their pole pieces surrounded by a co per body to cause it to be de-energized slow and to be re-energized slowly. After the completion of the sending in of a signal from a box circuit, the risin of the code lever on the stopping land 0 the code wheel closes the box circuit and these ma etsare energized and their armatures raise These ositions of the armatures are not disturbe by the closing 'ot the ole changer-circuit, due to the striking of t e contact 20 against the lever on the armature 19, which operates to reverse the polarity of the circuit, but the slowacting character 015 these ma nets is such that the short interval of time uring which the box circuit is open when its polarity is' being changed isinsufiicient to permit the. line relay armature or non-interference relay armature to drop.

Reference has been made in the foregoing specification to the normal direction current of the box circuit when it is in non-operatin condition. Thishas been called the norms direction current, or normal current, and when it is reversed and in condition for the operating box to sendin asignal, the direction of the current has beenreferred to as the reverse current, or reverse direction current, or abnormalized current. It is tobe understood that the present invention contemplates an apparatus in which the box circuit is of closed circuit type, conductin at such time'a certain kind of current, which in the described embodiment is a continuous current flowin in one direction, and that when a box in snc circuit is engaged in the operation of sendin in a signal, the current in such circuitis di ferent, and in the described embodiment is a direct current having a direction the reverse of the non-operating current. But such box circuit current might be of one character in its non-operating condition, and of a diflerent character in its operat" g condition. It is within the'purview o the invention that other difierences between the cnon operating current and the operating current might be resorted to with proper changes e of operation a results secured by the present invention, and for this reason, therefore, the non- .operating current is referred to by the broad term normal current, and the operating current is refe red to by the broad term of abnorrrahzed current, as the invention contemplates such variations within its purview.

Single bow-circuit system.-The fire alarm system as thus far illustrated and described contemplates a plant of considerable size. It

being possible to put as many as thirty boxes on each box circuit, it will be apparent that V a very large system is provided for. In many described, except that the trouble circuits are omitted, and the non-interference relay, which prevents the interference. of other box circuits with the operating box circuit, is

omitted, as well as the non-interference lines.

Referring to Fig. 10, the box circuit B, the pole changer PC, the line relay LR, and their connections, are all arranged as hereinbefore described. The signal connections, however,

are diiferent. The armature 16 of the line relay is provided with a second contact 300, which is connected by the wire 301 to the hinding post 302, in turnconnected by the wire 303 with the box signal 43, which may conveniently comprise the audible signal 44 and recording signal 45, as shbwn in Fig. 1. The

armature 19 and opens the pole changing oircuit by withdrawing the lever 22 from under the pin 20 on the shaft 27, driven by the spring motor 21. This d-energizes-the pole changer circuit as the circuit leads from the shaft 27 to the frame of the spring motor 21, and thence through the wire 33 to the pole changer, and back through the wire 34 to the binding post 35, connected to the far end of the box circuit battery 36. The sending in of the signal from the box circuit B then begins, and upon each de-energization of the line relay LR, the contact 300 supplies current to the wire 301 leading to the box circuit signal device 43, which leads back through the con-' nections described to the binding post 35,

connected to the far end of the box circuit" battery. KThe boxes are the same as the boxes above described. There is no necessity fora trouble indicator in connection with this box circuit system because the box circuit signal 43 will sound continuously as long as the box circuit remains open. Furthermore, inasmuch as there is no other box circuit connected with this'box circuit, there is no necessity for a non-interfering relay, as there is no other box circuit to interfere with the operation of this box circuit.

Having thus described the invention, what is claimed is 1. A- box for fire alarm systems having, in combination, a spring motor, a pull lever for winding up the spring motor, a non-interfer-- ence magnet, a polarized magnet, a box circuit including both said magnets in series, a code wheel operated by the spring motor, the polarized magnet having interconnecting members operating upon the breaking of the circuit to permit the non-interference magnet to stop the motor.

2. A fire alarm system having, in combination, a normally closed box circuit, a plurality of boxes in the box circuit, each box being provided with a code lever and wheel for actuating it, a magnet having an armature adapted to be interposed in front of the code lever, and a polarized device in the box cir- I cuit for allowing the armature to rise outof the field of the magnet and render the code lever inoperative upon reversal of the box.

circuit current, a relay in the box circuit, and a pole-changing device operated by the relay for reversing the polarity of the box circuit current on the starting of a box to send in a signal.

I 3. A fire alarm system having, in combina-' tion, a box circuit, a plurality of boxes in the box circuit, each box having provision rendering it inoperative to send signals on reversal of the box circuit current, a time relay and a trouble relay each having a screw feed, a pole-changer controlled by the time relay for reversing the polarity of current in the box circuit and for thereafter normalizing the current, a trouble indicator connected with the trouble relay, and means cooperating with the screw feed whereby each making and breaking of the box circuit acts to delay the normalization of the box circuit current and the operation of the trouble indicator through the time relay and the trouble for allowing it to move out of the field of the magnet upon reversal of the current.

5. A fire alarm box having, in combination, a box circuit, a spring motor, a lever for winding up the motor, means for sending in a signal comprising a code wheel operated by the-motor and a cooperating code lever, a non-interfering magnet, an armature for the non-interfering magnet normally maintained out of the path of the code lever and provided with a spring urging it into the ath of the code lever and out of the field 0 the magnet, a polarized magnet having an armature adapted to normally hold the armature of the non-interfering magnet in opera-' tive position in the field of its magnet and to allow it to move out of the magnetic field upon reversal of current through the polaring the circuit opening relays for opening all other box circuits and causing reversal of the box circuit current, and means for energizing the non-interference lines upon actuation of any non-interference relay.

7. A fire alarm system having, in ,combination, a plurality of normally closed box circuits, a plurality of boxes in each box circuit, each box having provision rendering it inoperative to send signals on reversal of the box circuit current and rovided with code signalling means for ma ing and brealn'ng the current, a time relay in each box circuit at the central station adapted to be actuated on each breaking of the circuit when a box sends in a signal, a pole changer controlled by the time relay for reversing the current after the first breaking of the circuit, and

for restoring the current to normal after completion of the signal, each operation of the time relay by the opening and closing of the box circuit acting to delay the normalizing of the current, a non-interference relay in each box circuit actuated in accordance with the code signalling means, non-interference lines, means operated by the non-interference relay of the circuit in which a box is operated for energizing the non-interference lines, and means operated on energization of the non-interference lines for reversing the current in all other box circuits.

v 8. A fire alarm system having, in combination, a pluralityof box circuits, a plurality of boxes in each box circuit, signal preventing means in each box circuit for preventiuginterference between boxes in the circuit, a non-interference device for each box circuit comprising a non-interference relay in the box circuit and a circuit opening relay adapted to be energized by the actuation of the non-interference relay, armatures for the relays constructed and arranged so that movement of one armature operates to hold the other armature in its normal position, noninterference lines connecting the circuit opening relays whereby upon operation of any one non-interference relay the circuit openin relays of all other circuits are actuated, an means for operating the signal preventing means in said other box circuits when the circuit opening relays are actuated.

9. A fire alarm system having, in combination, a plurality of normally closed box c1rcuits, a plurality of boxes in each box circuit adapted to send a signal by the making and breaking of the circuit, a trouble relay associated with each box circuit, a screw feed and a feed member connected with the trouble relay for engaging the screw feed, means for allowing the feed member to move over the screw feed when the box circuit is open and for resetting such member at the beginmn of the feed when the box circuit is close and means for short-circuiting the loop containing the boxes of box circuit if such member remains in engagement with the screw feed for an extended length of time so as toeliminate such box circuit from further participation in the government of the system. 10. A fire alarm system having, in combination, a plurality of normally closed box c rcuits, repeating means for the box c rcu ts operating upon opening of a box c1rcu1t,

means for short circuiting the loop containing the boxes of each box circuit, a trouble relay operable upon opening of a box c rcuit, and means operated by the trouble relay after a box circuit remains open longer thana predetermined time to'operate the short circuiting means of said box circuit 11. A fire alarm system having, in comblnation, a plurality of normally closed box circuits, repeating means for the box c rcu ts operating upon opening of a box c1rcu1t, means for short circuiting the loop contaming the boxes of each box circuit, a trouble relay having a part movable toward a posi-.

tion to operate said short circuiting means upon occurrence of an open box c1rcu1t, and constructed and arranged to be reset upon closure of the circuit, whereby the short c1rcuiting means of an open box circuit 1s operated after said circuit remains open longer than a redetermined time.

12. fire alarm system having, in combination, a plurality of normally closed box circuits, repeating means for the box circuits operated upon opening of a box circuit, short circuiting contacts for short circuiting the loop containing the boxes of each box cir- VERNON DURBIN. 

